Hippocampal volume is related to complexity of nesting habitat in Leach's storm-petrel, a nocturnal procellariiform seabird.

The hippocampal and telencephalon volumes of the nocturnal Leach's storm-petrel (Oceanodroma leucorhoa, n = 15) were compared with published data for food-storing and non-storing Passerines. The hippocampus to telencephalon ratio of Leach's storm-petrels is intermediate between food-storing and non-storing birds. Leach's storm-petrels taken from nesting burrows in wooded habitat had a larger relative hippocampal volume than those taken from burrows in an open meadow. Relative olfactory volume did not differ between woods and open-nesting storm-petrels. The larger relative hippocampal volume of storm-petrels may be associated with increased spatial demands of returning to their nests at night in the darker, more navigationally complex woods. It is not known whether the larger hippocampus in storm-petrels from the woods is due to selection on different subpopulations or whether experience in a more complex environment results in greater hippocampal volume. Hippocampal volume from the brain of one diurnal Procellariiforme, the northern fulmar (Fulmaris glacialis), fell within the range of non-storing species, which supports the view that hippocampal enlargement in the storm-petrel is related to the spatial demand of returning to the nest at night.

Differences in the accommodation stimulus response curves of adult myopes and emmetropes.

While the accommodation system has been implicated in myopia development, the nature of this relationship remains obscure. This study investigated the differences in accommodation stimulus response curves between adult myopes and emmetropes. Myopic subjects were classified according to age of onset and stability of their myopia. Accommodation stimulus response curves were measured using three different methods: (i) real targets presented at viewing distances of 4 m to 0.25 m, (ii) a target at 4 m viewed through negative lenses of increasing power, and (iii) a target at 0.25 m viewed through positive lenses of decreasing power. A Canon Autoref R-1 measured the accommodation responses at 5 levels of demand (increasing from 0 D to 4 D in 1 D steps). We found significant differences between the three methods used to stimulate an accommodation response in all subject groups, for example, accommodation lags at high accommodative demands were greatest for the negative lens series and least for the positive lens series. In addition, while differences between early-onset myopes, late-onset myopes and emmetropes were not observed, we did observe differences when myopic subjects were reclassified according to whether their myopia was progressing or stable. A reduced accommodation response to negative lens-induced accommodative demand was found in progressing myopes but not in stable myopes. These results provide further evidence for the link between myopia progression and inaccurate accommodation. The data also suggest that adult myopes with stable refractive errors show accommodation responses similar to that of emmetropes.

COMIDA: a radionuclide food chain model for acute fallout deposition.

A dynamic food chain model and computer code, named "COMIDA," has been developed to estimate radionuclide concentrations in agricultural food products following an acute fallout event. COMIDA estimates yearly harvest concentrations for five human crop types (Bq kg-1 crop per Bq m-2 deposited) and integrated concentrations for four animal products (Bq d kg-1 animal product per Bq m-2) for a unit deposition that occurs on any user-specified day of the year. COMIDA is structurally very similar to the PATHWAY model and includes the same seasonal transport processes and discrete events for soil and vegetation compartments. Animal product assimilation is modeled using simpler equilibrium models. Differential transport and ingrowth of up to three radioactive progeny are also evaluated. Benchmark results between COMIDA and PATHWAY for monthly fallout events show very similar seasonal agreement for integrated concentrations in milk and beef. Benchmark results between COMIDA and four international steady-state models show good agreement for deposition events that occur during the middle of the growing season. COMIDA will be implemented in the new Department of Energy version of the MELCOR Accident Consequence Code System for evaluation of accidental releases from nuclear power plants.